Analysis of Vibrations and Buckling of Conical Shell Homogeneous Orthotropic

, M.Sc. Thesis Sharif University of Technology Zafari, Danial (Author) ; Kouchakzadeh, Mohammad Ali (Supervisor)

Abstract

The purpose of this thesis parametric study the natural frequencies and the criti-cal buckling multilayer composites truncated cone with the effect of lateral shear deformation. For this purpose five-bending tensile deformation equation of motion of the truncated cone shell in a suitable coordinate system have been studied. Then solve the five-coordinate movement for power series-are consid-ered. The natural frequencies and critical buckling force for the various truncat-ed cones with four different boundary conditions are calculated and the results with the results of similar conical shells with the same boundary conditions, tak-ing into account the effect of lateral shear deformation and...

Wideband Doherty Power Amplifier with Designed Back-Off Power for Cellular Base Stations

, M.Sc. Thesis Sharif University of Technology Zafari, Ali (Author) ; Memarian, Mohammad (Supervisor) ; Safarian, Amin Ghasem (Co-Supervisor)

Abstract

The Emergence of modern wireless communication standards and the need to use the frequency spectrum efficiently has made communication system designers exert complex modulation schemes. One of the results of such designs that has a direct impact on the design procedure of power amplifiers is that there will be signals with high peak to average power ratio.The obvious consequence of this manner in the design of communication systems would be the reduction of power amplifier efficiency due to its operation in its back-off region. The solution will be to use load modulated power amplifiers such as Doherty amplifier which brings up the problem of limited bandwidth.In this thesis, we tackle this...

Assessment of water-energy-emissions nexus in wastewater treatment plants using emergy analysis

, Article Environment, Development and Sustainability ; Volume 25, Issue 10 , 2023 , Pages 11905-11929 ; 1387585X (ISSN) Modiri, M ; Haj Hasan, A ; Zafari koloukhi, H ; Rostami, F ; Tafazzoli, M ; Avami, A ; Sharif University of Technology

Springer Science and Business Media B.V 2023

Abstract

The aim of this study is to quantify the water-energy-emissions nexus in wastewater treatment plants (WWTPs). At first, energy auditing is done for two real WWTPs to find out the energy consumption of different plant stages and the energy-saving potentials. The power plant and carbon capture units are taken into account to assess the energy-emission nexus based on emergy flows. Then, the emergy analysis is applied to evaluate the environmental, economic and technical aspects. An emergy performance index (EmIGHG) is presented by the means of emergy flow diagram of the WWTP beside a power plant (considering the electricity production emergy cost) and carbon capture unit (considering the CO2...